1. Field of the Invention
The present invention relates to the field of furniture and in particular, chairs that have a backrest for added comfort when a user is seated in the chair.
2. Description of the Prior Art
The inventor is aware of the following prior art patents and published patent applications of which the inventor became aware during the prosecution of a previously filed patent application Ser. No. 13/947,007. The following 15 patents and published patent applications are relevant to the present invention:
1. U.S. Pat. No. 2,169,197 issued to Clair S. Reed on Aug. 8, 1939 for “Seat Structure” (hereafter the “Reed Patent”);
2. U.S. Pat. No. 2,186,301 issued to Harold C. La More on Jan. 9, 1940 for “Upholstered Seat Beat Structure” (hereafter the “La More Patent”);
3. U.S. Pat. No. 2,265,901 issued to James W. Greig on Dec. 9, 1941 for “Seat Structure For Vehicles” (hereafter the “Greig Patent”);
4. U.S. Pat. No. 3,896,531 issued to DeWitt Y. Gorman on Jul. 29, 1975 for “Upholstery System Method And Apparatus” (hereafter the “Gorman Patent”);
5. U.S. Pat. No. 4,815,789 issued to Fred Marcus on Mar. 28, 1989 for “Chair Kit” (hereafter the “Marcus Patent”);
6. U.S. Pat. No. 4,828,320 issued to Herbert C. Saiger on May 9, 1989 for “Chair Frame And Cushion Assembly” (hereafter the “Saiger Patent”);
7. U.S. Pat. No. 5,316,375 issued to William R. Breen on May 31, 1994 for “Back Support And Internal Frame” (hereafter the “Breen Patent”);
8. U.S. Pat. No. 5,931,538 issued to Alain Cayet at al. on Aug. 3, 1999 for “Vehicle Seat Element Including A Cover Tensioned Over A Metal Frame” (“hereafter the “Cayet Patent”);
9. U.S. Pat. No. 6,726,691 issued to Marcus C. Koepke et al. on May 4, 2004 for “Chair Back Construction” (hereafter the “Koepke Patent”);
10. U.S. Pat. No. 6,752,464 issued to Chuen-Jong Tseng on Jun. 22, 2004 for “Modular Furniture Frame” (hereafter the “Tseng Patent”);
11. U.S. Pat. No. 7,708,345 issued to Daniel Grabowski et al. on May 4, 2010 for “Recliner” (hereafter the “Grabowski Patent”);
12. U.S. Pat. No. 8,061,771 issued to Gregory W. Goeckel on Nov. 22, 2011 for “Supportive Back Overlay For Wheelchair Back” (hereafter the “Goeckel Patent”);
13. U.S. Pat. No. 8,366,044 issued to Hector Noel Marini on Feb. 5, 2013 for “Removable Back Shell For An Aircraft Seat” (hereafter the “Marini Patent”);
14. U.S. Pat. No. 6,491,345 issued to Shepard on Dec. 10, 2002 for “Seat Having Interchangeable Inserts” (hereafter the “Shepard Patent”);
15. Scheurer et al. Published Patent Application 2010/0019558 published on Jan. 28, 2010 for “Buoyant Pool Chair With Sealed Frame” (hereafter “Scheurer Publication”).
The Marcus Patent discloses the following relevant pieces of information:                “The present invention is directed to assemblies and sub-assemblies for incorporation into a chair, to a chair kit that comprises these assemblies and sub-assemblies, and to the chair itself. It includes a substantially rectangular seat and back cushion sub-assemblies for incorporation into a chair. The seat and back cushion sub-assemblies may be readily removed from and replaced onto the chair itself, thereby facilitating the replacement of a rigidifying inner foam pad. The invention also includes a novel means of securing cushions to the chairs. This means comprises a rigid, substantially rectangular seat frame member having laterally opposed slots along its inner portion. At least one fixedly secured and at least one movably secured screw-receiving leg is attached to this seat frame member.”        
The Cayet Patent is for a vehicle seat element including a cover tensioned over a metal frame. The patent discloses:                “A vehicle seat element is covered by a cover having four lateral panels which are folded over a rigid frame. Two of the lateral panels that are opposite each other, present in the vicinity of their free edges buttonholes which are engaged on tabs that are free from sharp edges and that are secured to the rigid frame. An inextensible flexible cord is stitched along the free edges of the cover, between said free edges and the corresponding buttonholes.”        
The Koepke Patent discloses a chair construction which has the metal frame incorporated into the chair. Specifically, the patent discloses:                “A chair back is disclosed and includes a mesh material connected to a two-piece carrier, the carrier being deformable and stretchable. The carrier has a bottom edge including a groove and is engageable by tabs attached to a transverse member of a chair frame assembly. The upper ends of the carrier each includes an opening for receiving a spherical end portion of the upper end of the chair frame assembly. Engagement of the carrier with the chair frame assembly is accomplished by stretching the carrier and mesh between the transverse member and the spherical end portions. The chair back includes a lumbar support which is mounted to slide along the side edges of the carrier and along vertical supports of the chair frame assembly, the lumbar support causing the chair to tension forwardly. The chair back is pivotal under the influence of a chair user and is pivotally connected to the chair seat so as to cause the chair seat to also pivot in response.”        
The Grabowski Patent for a recliner discloses:                “One embodiment of the invention includes a reclining chair that includes: a chair frame comprising front and rear frame members, two parallel side frame members each side frame member attachable to the front and rear members; a seat supported by at least two frame members; a backrest; a pair of legs, wherein the frame members are connected to the legs; a first and second recliner assembly comprising a bracket, the bracket is attachable to the backrest enabling reclining movement of the backrest as the bracket moves through a correspondingly shaped bracket slot in a recliner base plate, wherein the bracket rotates about an axis that approximates the position of the rotational axis of the hip of a seated user.”        
The Reed Patent discloses a solid metal frame assembly built into the chair so that there is not a separate frame assembly built into the cushion.
The La More Patent discloses: improvements in the upholstered seat back structure.
The main objects of this invention are: First, to provide a back structure which is well adapted for theater and auditorium seats and the like, and one which, while attractive in appearance, permits ready removal of changing of the upholstery; Second, to provide a seat back structure of this character in which the upholstery may be very quickly applied by relatively unskilled workmen. Third, to provide a seat back structure which may be economically produced mainly of sheet metal stampings and at the same time one in which the parts are so arranged that they do not spring or buckle when made of light gage metal.
The Greig Patent discloses a seat structure for vehicles. Referring to FIG. 3, there is a spring frame assembly that is built into the back of the seat as illustrated. The patent further discloses: “In the drawings there are shown, by way of example, vehicle seat structures constructed in accordance with certain embodiments of the present invention. The structure shown therein comprises generally a back rest, the lower cushion, and means for securing the same together. The back rest and the cushion are so constructed that each of them may be manufactured separately and assembled together after each of them is completed. When assembled together the back rest and the lower cushion provide a single unit. When assembled in a vehicle, the lower cushion is not removable and it remains firmly in place.
The Gorman Patent discloses the concept of having the frame backing built into the entire chair with the cushion effectively fit over that frame backing as best illustrated in FIG. 2.
The Saiger Patent discloses a chair frame and cushion assembly. The frame member is built into the chair itself and not into the separate cushion.
The Breen Patent discloses a back support and internal frame. Specifically, the patent discloses: “There is provided a frame for use with a back support that provides lateral support to an individual while seated to encourage a correct sitting posture, and that also provides lumbar support to the individual that varies according to the individual's size. The frame includes wing portions that act as lateral supports and as torsion bars to cause the center portion of the frame to become convex to support the lumbar region of an individual resting against the back support incorporating the frame. The frame can be incorporated into a portable support unit or to a support unit that is an integral part of a chair.”
The Tseng discloses a framework for a chair. It further discloses that the seat frame unit includes a parallel pair of upright side frame parts, each of which has front and rear ends opposite to each other in a first direction. The side frame parts are spaced apart from each other in a second direction transverse to the first direction. The seat frame unit further includes a pair of rear coupling members that are connected to the rear ends of the side frame parts, a pair of front coupling members that are mounted on the front ends of the side frame parts, a pair of mounting members that are mounted on the front coupling members, and a bracing rod. The rear coupling members are used to mount the backrest frame unit on the seat frame unit, whereas the mounting members on the front coupling members are used to mount the leg cushion on the seat frame unit.
The Goeckel Patent discloses a supportive backrest attachment for a wheelchair. The patent discloses: “A supportive back rest for attachment to an original equipment back rest of a wheelchair to enhance the supportive characteristics of the wheelchair back rest. The supportive back rest includes a cushion, a suspension element and a cover. The cushion and one side of the suspension element are positioned in the cover. An opposed side of the suspension element is exposed and defines a space between it and the cushion. The suspension element slips over the upper edge of the original equipment back rest of the wheelchair to suspend the supportive back rest in position behind a seated user. The suspension element can be attached to the cover or can be attached to the cushion by molding or through attachment anchors.”
The Marini Patent discloses the concept of having the metal portion incorporated into the chair and thereafter the cushion on top of it.
The Shepard Patent is essentially a chair which has a reinforcing section in the seat and also a separate reinforcing section in the backrest. In each case, the reinforcing section is fully exposed and is not contained within any portion of a cushion or any other seating member placed on the seat or against the back of the chair.
The Scheurer Publication discloses a buoyant seat which is formed of overlapping layers of buoyant cushion material. Each buoyant cushion is formed by a pair of overlapping layers of buoyant material, preferably closed slabs of cell polyurethane foam having a given density.
The above described patents and published applications do not disclose or reveal the present invention. Further, during the prosecution of a prior patent application, the inventor was made aware of the following patents:
U.S. Pat. No. 860,632 issued to Breithut on Jul. 23, 1907 for “Chair Back Hinge”.
U.S. Pat. No. 873,265 issued to Petroskey on Dec. 10, 1907 for “Metallic Chair”.
U.S. Pat. No. 1,711,959 issued to Morin on May 7, 1929 for “Chair”.
U.S. Pat. No. 2,960,152 issued to Wendel on Nov. 15, 1960 for “Blocked Furniture”.
U.S. Pat. No. 3,896,531 issued to Gorman on Jul. 29, 1975 for “Upholstery System Method and Apparatus”.
U.S. Pat. No. 4,365,840 issued to Kehl et al. on Dec. 28, 1982 for “Seat With Back Cushion Attachment”.
U.S. Pat. No. 4,367,897 issued to Cousins on Jan. 11, 1983 for “Adjustable Seat for the Handicapped”.
U.S. Pat. No. 4,746,168 issued to Bracesco on May 24, 1988 for “Motor Vehicle Seat”.
U.S. Pat. No. 5,478,133 issued to Tidwell, Jr. on Dec. 26, 1995 for “Motion Furniture Construction”.
U.S. Pat. No. 5,570,874 issued to Tornero on Nov. 5, 1996 for “Furniture Spring Assembly With Elastic Webbing”.
United Kingdom Patent GB 2151131 issued to Hawtree et al. in July 1985.
There is a significant need for an improved backrest for a seat or other furniture item where the item includes one or more cushions against which a person places his back after the person is seated on the furniture item.